Q - my 2008 f250 6.4 l only took half the coolant it was supposed to during a change. it should take 30.6, it only took half,why? Bob
The main reason is that you usually aren’t able to completely drain the coolant system when you do a change. The radiator will drain, but lots of coolant is still left in the engine that is quite a bit more difficult to drain. Between the egr coolers, oil cooler, engine block, and heads there is lots of capacity for coolant. I wouldn’t be alarmed. What you observed is perfectly normal.